Injection molding machine



7, 1943. w. R. TUCKER 2,327,227

INJECTION MOLDING MACHINE Filed Feb. 6, 1941 5 Sheets-Shet 1 INVENTORWARREN R. TUCKER Aug. '17, 1943. w. R. TUCKER 2,327,227

INJECTION MOLDING MACHINE Filed Feb. 6, 1941 5 Sheets-Sheet 2 INVENTOD\NARREN Q. TUCKEQ MQQM A TonNEvs Aug. 17, 1943- w R TUCKER INJECTIONMOLDING MACHINE Filed Feb. 6, 1941 5 Sheets-Sheet 5 IIEIT 7 Aug. 17,1943. I w. R. TUCKER 2,327,227

INJECTION MOLDING MACHINE Filed Feb. 6, 1941 5 Sheets-Sheet 4 9 1 r I II 1 5 4 III 13 WAQQEN R. TIIKEP.

ATTORNEYS Aug; 17, 1943. w. R. TUCKER 2,327,227

INJECTION MOLDING MACHINE Filed Feb. 6, 1941 5 Sheets-Sheet 5 23!FIB-:13 238 INVENTOQ WADQEN Q. TUCKER ATTORNEYS Patented Aug. '17, 1943INJECTION MOLDING MACHINE Warren R. Tucker, Dayton, Ohio, assignor toThe Hydraulic Development Corp. Inc., Wilmington,

Del. a corporation of Delaware Application February a, 1941, Serial No.377,708

35 Claims.

This invention relates to plastic injection machines, and particularlyto those machines which are automatic in their operation.

An object of the invention is to provide a plastic injection machinewherein a plurality of molds is continuously advanced by successivesteps into operative relation with respect the injection cylinder, andwherein the injection of plastic material into the molds is caused bymovement oi the injection cylinder with respect a stationary plunger.

it is another object of the invention to provide a plastic injectionmachine in accordance with the foregoing object wherein the movement ofthe injection cylinder is caused by a hydraulically actuated plungeroperating through the molds, whereby the molds are retained inengagement with thenozale of the injection cylinder and. closingpressurels applied upon the molds.

- it is another object oi the invention to provide a plastic injectionmachine wherein a plurality of molds is carried upon a turret in amanner that the molds can he raised i'rom the turret and he brought-intoengagement with the injection cylinder.

It is another object oi the invention to provide a plastic injectionmachine in accordance with the foregoing object wherein a hydraulicallyactuated plunger raises the m'oldsirom the turret and causes engagementthereof with the titles tion cylinder in order to move the cv'lirnlerwithrespect a stationary injection plunger for in-- jecting plasticmaterial into the molds.

it is still another ohject of the invention to provide an injectioncylinder oi a plastic injection machine which is carried upon areciprocahle head, which head is retained in a specific position withrespect an injection plunger by means oi a hydraulic motor havingpressure con tinuously applied to one side thereof, and wherein aplurality of molds is carried. into alignment with the cylinder Toymeans or a rotating turret so that a hydraulically actuated ramassociated with the turret can lift the molds into engage rneht withthe, cylinder and cause movement oi the cylinder with respect theplunger, the iioid pressure in the hydraulicmotors associated with thecylinder providing the pressure required for sealing the nozzle upon themold and for applying clamping pressure between the mold halves.

the injection cylinder toy a mechanism. actuated in response to thereciprocation oi the reciprocal head upon which the cylinder is mounted,and which reciprocation feeds material into the cylinder in proportionto the stroke of reciprocation of the cylinder.

It is another object of the invention to provide a plastic injectionmachine having a turret rotatably mounted thereupon which is constructedand arranged for carrying a plurality of molds, andwherein the molds areadapted to engage cam tracks during their rotation upon the turret sothat during a certain portion or the rotation of the molds by the turretthe molds will he in engagement with the cam tracks in a manner that thecam tracks will force the molds open to permit work pieces to he ejectedtherefrom and will again close the molds when they are brought intoposition adjacent the plastic injection unit of the machine. v

I It is anotherobject oi the invention to provide a plastic injectionmachine wherein the rain foregoing object, which electrical system willhe controls for insuring proper iunctioning oi the machine and iorhalting the machine during certain intervals thereof it some taultshonld occur.

it is another object oi the invention to pro vide a hydraulicallyactuated mechanism which is adapted. to function upon two adjacent moldsin a manner that a WDiTi piece is ejected from one oi the molds when themolds are opened and the mold adjacent thereto is adapted he closed,these events occurring during the injection cycle or the machine and themechanism being asso== ciated with a mechanism for advancing moldssuccessively into engagement therewith.

It is another object of the invention to pro vide a mechanism inaccordance with the fore going object Whichoperates concomitantly withthe stroke of the injection ram oi the plastic in jection machine.

Further ohjects and. advantages will become apparent from the following"description and from the drawings.

In the drawings:

Figure 1 is a vertical cross-sectional view of a plastic injectionmachine constructed in accordance with the teachings of this invention.

Figure 2 is an elevational view of the feeding mechanism for feedingmaterial into the injection cylinder of the .machine.

Figure 3 is a vertical cross-sectional view of a portion of the machineand is taken along line 3-3 of Figure 1. v

Figure 4' is an,end elevational view looking in the direction of thearrow 4 in Figure 3, showing the mechanism which carries the work piecefrom the molds after ejected. a

Figure 5 is a cross-sectional view of a portion of the machine takenalong line 55 of-Figure '1.

Figure 6 is a cross-sectional view of the yoke mechanism for operatingthe work piece removing mechanism and is taken along line 6-6 of Figure4. 4

Figure 7 is a horizontal cross-sectional view' taken along line 1..1 ofFigure 1.

Figure 8 is a horizontal cross-sectional view taken along line 8-8 ofFigure 1, looking upwardly-at the'turret of the machine.

Figure 9 is a somewhat diagrammatic view showing the development of thecam track for opening and closing of the molds and the relation thereofto the ejecting mechanism.

Fi ure 10 is a cross-sectional view taken alon line Ill-l0 of Figure 9.

Figure 11 is an end elevatlonal view looking in the direction of thearrows llii of Figure 9.

Figure 12 is. a diagrammatic view of the hydraulic system used upon theinjection machine spect each other. The upper ends of the strain rodsand 26 are connected by means of a stationary head 29, the bolts 30 and3| respectively securing the head 29 between said bolts and the collars-32 and 33 respectively.

Aninjection plunger is carried by the stationary head 29 and is securedthereto by means of the bolt 35 and the collar 36. A reciprocable head31 is positioned upon the strain rods 25 and 26 and is carried below theinjection plunger 34. This reciprocable head 31 has a pair of verticallyextending bores 38 and 39 which are of larger diameter than the strainrods 25 and 26 over which they extend in an axial relation.

The strain rod 25 has a collar 40 secured thereon, wh ile the strain rod26 has a collar 4| secured thereon. These collars 40 and 4| are oflarger diameter than the respective strain rods and are of such diameteras to slidably engage the bores 38 and 39' provided in the head 31 sothat the collars 40 and 4| act as pistons within the respective bores 38and 39. A sealing member closes the upper end of the'bore 38, while asection and partially in elevation of one of the mold releasingmechanisms of Figure 14.

Figure 16 is a cross-sectional .view of the mold lifting and ejecting=mechanism of the other of the mechanisms of Figure 14.

In this invention the plastic injection machine consists of a base orbed 50, having side walls H and a bottom portion. l2 thereby forming acompartment 13 in which a high pressure fluid pump, actuated by anelectric motor 84, can be positioned. The storage tanks for theactuating fluid for the injection press can be arranged within thiscompartment i3, or the compartment may have dividing walls therein whichof themselves provide the desired fluid storage tanks.

Referring to Figures 1 and '12, Figure 1 discloses the mechanicalmechanism of the press and Figure 12 discloses the hydraulic system forthe press, the machine consists of a hydraulic motor 15 having acylinder I6 wherein a piston i1 reciprocates. The piston 11 carries aplunger or ram I8 which extends through an end plate l9 for the cylinder16. The end plate I9 is secured to the bed In by means of suitable bolts20. A sealing member 21 is positioned around the plunger or ram 18 andis retained upon thefend plate 19 by means of the bolts' 22. motor I5.isprovided with hydraulic fluid connections 23 and 24 at the opposite endsthereof.

A pair of strain rods 25 and 26 are secured to the bed 10 by means ofthe bolts 21 and 28 respectively. These strain rods extend upwardly fromthe bed Ill and in parallel relation with re- The hydraulic sealingmember 43 closes the upper end of the bore 39. A sealing member 44closes the lower end'of the bore 38 while a sealing member 45 closes thelower end of the bore 39.

The hydraulic motors thus provided by the bores 38 and 39 and carriedbythe head 31, are provided with fluid passages for connecting the same toa source of pressure fluid. The bore 38 which forms part of thehydraulic motor 46, is provided with passageways 41 and 48 at theopposite ends thereof, while the bore 39 forming a part of the hydraulicmotor 49 is provided with fluid passageways 50 and 5| respectively inthe upper and lower ends thereof. A conduit 52 cross-connects the lowerportions .of the bores 38 and 39, while a conduit 53 cross-connects theupper portion of these bores whereby the hy draulic motors will beactuated in parallel when fluid is directed to the respective ends ofthe motors 46 and 49.

The head 31 carries an injection cylinder 55,

which consists of a cylindrical body 56 having a bore 51 which is inaxial alignment with the bore 58 provided in the head 31, which bores 51and 58 are in axial alignment with the injection plunger 34. The body ofthe injection chamber 56 is provided with a plurality of annular grooves59 through which fluid is circulated for heating plastic material withinthe injection chamber or bore 51. It is to be understood that while theannular grooves or chambers 59 have been specifically disclosed as fluidcirculating chambers, yet they can be dispensed with and other forms ofheating apparatus be used for heating the injection cylinder 56. Suchheating apparatus is well known in the art and is therefore not fur"ther disclosed. Injection chamber 56 is surrounded by the heatinsulating wall 60 which in turn is enclosed in a material jacket 6|.The injection chamber body 56 is removably secured to the head'31 bymeans of the bolts 62 The forward end of the injection chamber 51terminates in an injection nozzle 63, which nozzle is removable topermit replacement and cleaning thereof. The nozzle 63 is provided witha round head portion 64 which is adapted to engage a socket in the moldsadvanced into alignment with the nozzle 53 for sealing engagementtherewith during the injection cycle.

respect the injection plungen As will be hereinafter described','the'injection cylinder 55 is reciprocal with respect the injection plunger34 for ejecting material from the cylinder-chamber 51 'into the moldspositioned adjacent the nozzle 63. The plastic material must thus be fedto the bore 51 ofthe injection cylinder 55 in proportion to the quantitywhich is ejected from the bore upon each stroke of the cylinder 55. Thismechanism consists of a feeding hopper which is suitably secured uponthe stationary head 29. The

' feeding hopper 65 has a worm or screw 68 in the extends intocommunication with the injection chamber 51 within the injectioncylinder 55. The conduits 6'7 and 88 and the bore 18 provide means forconducting plastic material from the hopper into the'bore 5'! of theinjection cylinder.

In orderto forward material from the hopper thin quantities which willbe in proportion to the material which is ejected from the bore 51 arack is secured to a bracket 12 extending from the conduit t8 so thatthe rack H is reciprocated throughout the same stroke of reciprocationas the head it, as will be hereinafter described more completely. Therack it engages a gear it suitably journaled upon the hopper t5, seeFigure 2. The gear it carries a ratchet tooth it which is retained inengagement with a ratchet wheel with mounted upon the end oi" the screwshaft A leaf spring it retains the ratchet tooth it in engagement withthe ratchet wheel it so that upon downward movement of the rack "M theratchet tooth 'i'twill engage the ratchet wheel and thus rotate the workwithin the feed hopper so that material will bated through the conduittill, During the upstroke oi the reel; it the gear 73 will rotate freelyabout the ratchet wheel l5 since at this time the ratchet tooth willride over the teeth of the ratchet gear. It may thus be seen that for adefinite stroke oi recip rocation oi the injection cylinder with respectthe injection plunger that the rack it will rotate the worm or screw apredetermined number of revolutions, whereby a predetermined quantity oimaterial will be fed through the conduit til" into the injection chamberill, and

which quantity of material will be in direct pro= till) that they can belifted by means of the depending portion during certain portions of theinjection cycle as will be hereinafter described.

A plate is secured to the turret I1 and may be either adjacent the molds82 or can surround the same; This plate 81, surrounding the molds 82,being provided with an opening of the same di ameter as theopening 88 inthe turret 11 so that the depending portion 85 or the molds 82 canextend therethroughj The plates 8'! carry vertically extending rods 88secured thereto in parallel relation and adjacent the molds 82.Preferably, the rods 88 are diametrically opposite each other whenpositioned adjacent the molds The lower halves 84 of the molds 82 areprovided with extending bosses 88 through which the rods 88 extendin'suitable bores. The upper halves 83 of the molds 82 are provided withexturret 11, or when the upper hall 83 is reciprocated vertically withrespect the lower half 85 during opening and closing oi the mold 82,which operation will be more fully described.

The lower halves 84 of the molds 82 are also provided with rollers 98positioned diametrically opposite each other upon the mold half 8d, andare suitably journaled upon stub bearing shafts provided in the lowerrnold half 8t. The upper mold halves iii are also provided with rollers92 which are positioned diametrically opposite each 'of the turret it;These earn tracks and lit are adapted to be engaged by the rollers tiand lit provided on the lower and upper mold halves lid and Mrespectively when the mold t2 is rotative= ly carried by the turret itin its circuit of ro tation.

The inner cam tracir t3 is supported by a spider t5 carried upon thestrain rod it whereby the cam tract: tt is stationarily positioned withrespect the turret ill and is vertically arranged with respect'thesurface of the turret 'l'l. The outer cam track. 9 5 is carried upon aplurality of rods, see Figures 5 and 7, which is threaded into the baseit; The outer carn track li i'carries a plurality of bosses it! which isjournaled upon the vertically positioned rods lit and is adjustablymounted by means of the bolts lit. The

.inner cam traclt $53 is adjustably carried upon r the strain rod it andis secured in position there rod The collar lit thus becoming the thrustmember and the hearing it becoming the thrust hearing for supporting theturret it.

A plurality of molds consisting of an upper hall and a lower hall. iscarried by the turret ii. The lower half t l of each of the molds isprovided with a depending portion 85 which extends through openings tilprovided in the turret l. The molds are e uidistantly spaced around thesurface of the turret il and are ar ranged loosely upon. the surface ofthe turret so on by means of the bolts The cam tracks tilt and lit arespaced from the upper face of the table of the turret "ill a sufii cientdistance that the rollers ti on the lower inold halves il -i canengagethe under surface of the tracks tit and lit. The under surfacesltd of the tracks and 9d are parallel to the upper surface of the tableof the turret ll so that when the rollers ti of the lower mold halves lit engage the surfaces tilt, these lower mold halves are retained uponthe upper surface of the turret table. The upper surfaces Hill of thecam tracks and t l have an inclined portion Hi2 which when engaged bythe rollers ill on the upper mold halves causes the upper mold halves toleave the lower mold halves 3t and thereby open the molds The projectionof the cam tracks the cam tracks levels off into a horizontal portionI03 which is parallel to the lower surfaces -IOI. This horizontalportion E03 then enters into a declining surface I04 whereby the uppermold halve 83 are permitted to return into engagement with the lowermold halves 84 when the mold are indexed by means of the turret.

To insure closure of the molds 02 when-passing over the decliningsurfaces I04 of the cam tracks 93 and 94 a pair of short cam tracks ispositioned vertically adjacent the cam tracks 93 and 94 and has lowersurfaces I06 thereon which are complementary to the surfaces I04 on thecam tracks 93 and 94 but are spaced from the surfaces I04 a sufficientdistance that the rollers 92 upon the mold halves 83 may passtherebetween. This arrangement thereby provides a definite cam slotthrough which rollers of the upper mold halves must pass in order tore-engage the lower mold halves The short cam tracks I05 are pivotallymounted upon the cam tracks 93 and 94 by means of the depending ear I01which are pivotally secured to the cam tracks 93 and 94' by means of thepins I08. The forward end of the short cam track I05-engages a stopmember I09 and is retained in engagement therewith by means of thecompression spring I I0. The spring IIO provides resilient means wherebythe forward end of the cam tracks I05 may lift with respect the camtracks 93 and 94, should the upper mold half 83 refuse to engage thelower mold half 84 due to some obstruction between the mold halves.

A lever l I I is carried by the forward end of the cam track H andengages an electric switch M2 and normally retains the switch in closedposition: When the forward end of the cam track W5 is raised due toincomplete closing of the mold halves 83 and 04; the electric circuitwill be broken through the switch l I2 to thereby halt operation of theinjection machine in a manner which will be hereinafter described.

A mechanism for ejecting work pieces from the mold while the molds arein openposition is provided vertically adjacent the cam tracks 93 and 94and is more specifically positioned vertically adjacent the horizontalland area 33 of the cam tracks. sists of a double acting hydraulic-motor H3 having fluid connections H4 and H5 at opposite ends thereof.The piston of the hydraulic motor H3 carries a plunger H6 which extendsoutwardly of the hydraulic motor H3 and is adapted to reciprocate withrespect the upper mold half 83 when brought thereadjacent by indexing ofthe turret. The hydraulic motor H3 is carried upon the stationary head29 of the press and is suitably secured thereto by means of the bolts IH. The hydraulic motor H3 is positioned vertically above the mold 82when the mold is indexed below the same, and the position is such fromthe upper mold half a mechanism is .The ejecting mechanism conejectionplunger. This pan H8 is carried upon rollers II9 which are guided intracks I20 which are positioned adjacent parallel sides of the pan H8.The forward end of the pan H8 is provided with forwardly extending armsI 2I adjacent each side of the pan which are engaged by a yoke E22. Theyoke is provided with a slot I23 which engages a pin I24 interconnectingthe yoke I22 with the arms I2I. The lower end of the yoke I22 isprovided with a bellcrank lever pivoted at I25. The end of the bellcranklever is connected to a double acting hydraulic motor I26 by means of alink I21, which link interconnects the plunger I28 extending from thehydraulic motor I26 and the pivot connection I29 on the end of thebellcrank lever.

The hydraulic motor I26 is provided with fluid connections I30 and I3Iat opposite ends thereof for reciprocation of the plunger I28, and thushorizontally reciprocating the pan H8 through the bellcrank lever.

-When the plunger I28 is moved in a downward A direction, as viewed inFigure 3, the yoke I22 will carry the pan IIB outwardly from between theopen mold halves 83 and 84 to an extent wherein the rollers I I9 will bedirected into the curved forward end I32 of the roller tracks I20,whereby the pan I I8 will be tilted to empty the work piece therefromwhich has been ejected into the same from the upper mold half 93 when inposition adjacent the same. The outer cam track 94 is provided with asuitable window or opening I33 through which the pan H8 can bereciprocated into adjacent relation between the open mold halves 03 andB4.

In order to indicate the presence or absence of a work piece in the panI l 9, and thereby insuring continuation of the operation of theinjection machine, a comb E34 is pivotally mounted at I35. This comb'l34 carries a lever I36 which engages an electric switch 031, whichswitch is normally open but which is momentarily closed when the workpiece passes under the comb I34. If a work piece is present In the panHi3 when removed from between the open mold halves/the closing of theswitch l3! will provide circuit for completion of operation of theinjection machine, whereas, if a work piece is absent from the pan IIBthe switch l31 will not be momentarily closed, whereby the mechanism forcompleting the circuit, establishing circuit relation to the maincontrol of the injection machine, will not be operated and the injectionmachine will halt operation before the beginning of a new injectioncycle.

The injection machine just described is arranged in a manner whereby theturret 11 has a table thereof arranged horizontally between thevertically positioned ram I8 and the injection cylinder 55. retl'i, areadapted to be advanced successively into alignment with the injectioncylinder 55 and the ram It so that when the ram I8 is reciprocated bythe hydraulic motor I5, the mold 82 will be lifted from the table of theturret 11 and brought into engagement with the nozzle I53 of the Icylinder 55 to reciprocate the bore 51 thereof The molds 02, carriedupon 'the turchamber'5I will mold 82. v

The injection cylinder 55 and the ram I8 are thus positioned in axialalignment and are vertically arranged at the molding station A, seeFigure 7. The hydraulic motor 3 for operating the ejection plunger II 6is vertically adjacent a mold carried upon the turret TI and is in.axial alignment therewith, the ejection station being indicated at B,see Figure 7. The station indicated at C, see Figures 7 and 9, isastation wherein the upper and lower mold halves are still in theirspaced relation to permit manipulation of the mold surfaces either forcleaning the surfaces or for positioning inserts within the mold. Awindow H38 is provided in the cam track 94 to permit access into theinterior of the mold 82 when adjacent the station C. A suitableautomatic mechanism can be provided for placing the be ejected therefrominto the inserts within the molds while adjacent station The mechanismfor indexing the turret 'l'i consists of a Geneva wheel Mil having aplurality u of'radial slots l ll'. An electric motor Mt! carries an armM3 upon the shaft Mil which is rotated by means of the motor 42. The armM3 carries a roller M which engages the radial slots Mi during rotationthereof bythe arm i143 in order to advance the Geneva wheel a.determined arc of movement and thereby indexing the turret ill adetermined are of movement. This Geneva type of indexing mechanism iswell known in the.

art and therefore further description. is not deemed necessary.

The indexing mechanism, however, rotates the turret ll periodically tobring successive molds adjacent the various' stations A to-E inclusivewhereby the mold is operated and various functions performed thereon, asheretofore described, which functions are coordinated to occur during asingle cycle of operation of the injection machine.

To insure the exact positionof the turret I! with respect the injectionplunger H6 a turret locking mechanism is provided. It can readily beappreciated that since the 'sprue opening in the mold is very small thatthe axial positioning of the mold adjacent the ejector plunger II6 mustbe accurate to prevent damage to the sprue opening. The turretlockingmechanism consists the cam I53 will engage the bellcrank lever I 49 toretract the plunger I46 from the hole I55.

thereby releasing the turret 11. and permitting the indexing mechanismto index the turret. The cam I53 will release the bellcrank lever I49before the turret IT has completed its indexing motion so that theplunger I46 will be spring pressed against the lower face of the turret11 to permit the plunger I46 to re-enter the next successive hole Iimmediately upon the proper axial relation being obtained between thehole I55 I and the lunger H6, thereby lockin the turret H in its newlyindexed position.

The hydraulic circuit for the press just described consists of avariable delivery constant speed fluid pump I56 which is driven by theelectric motor E4. The pump I56 is provided with a pressure control l5?which regulates the maximum pressure delivered by the pump A55. Variabledelivery pumps having pressure control are 4 well known in the art and.therefore further description of this item is not deemed necessary sinceany of the well knownpumps having pressure control can be utilized inthe system.

A reservoir let is provided for the fluid which is to be circulated tothe various actuating elements of a hydraulic system. The pump M5delivers through the discharge conduit it!) to a 4-Way valve itt throughmeans of a branch conduit ltl. The 4-way valve it!) is connected to thefluid inlets 23 and 2d of the hydraulic motor i5 by means of theconduits W2 and 1163. The

conduit ate also conducts fluid to the inlet N5 N5 of the ejector motor-II3 flows therethrough at a lesser rate than to the hydraulic motor H5through the conduit I64 and the passage Hi. This arrangement permits theejector motor to lag in operation behind the hydraulic motor I26. Thisarrangement is provided to permit the hydraulic motor I26 to move thecollecting pan I I8,

of a plunger I 46 which is reciprocably guided within a casing I4! andthe bed I0 of the press. The casing I4! is suitably secured to the bedI0 and is also provided with a slot I48 in the side wall thereof throughwhich a bellcrank lever I49 can extend. The bell crank lever I49 ispivoted on a pin I50 Which is carried by the casing I41. One end of thelever I49 engages a pin I5I carried by the plunger I46, a slot I52-being suitably The opposite provided in the end of the lever. end of thebellcrank lever I49 is engaged by a cam I53 which is carried upon themotor shaft I44. A compression spring I54 is positioned between the bedI6 and the end of the arm of the bellcrank lever I 49 for normallyurging the plunger I46 in an upward direction into engagement with ahole I55 in the turret'l'l.

The cam I53 is arranged with respect the arm This valve I'IIIcommunicates with the fluid inlet. connections 50 and 5| of thehydraulic motor 49 by means of the conduits III and I12 respecdisclosedin Figure 3, into position between the openmold halves 83 and 84 beforethe ejector plunger II6 will eject the work piece from the upper moldhalf 83. The orifice or choke valve I61 can be manually varied tocontrol the difv The fluid pressure discharge line I59 also conductsfluid under pressure to a 4-way valve I'll).

'tively. An exhaust conduit [13 connects the between the mold halves.

valve no with the fluid storage tank tea. The valve 113 is normallypositioned with the fluid connection continuously established betweenthe fluid inlet line-l59 and the fluid connecting coniduit 512, wherebyfluid under pressure is continuously applied to the under side of thepiston M and within the chamber 114 whereby the normal position of thehead 31 with respect the piston 51 is with the piston ii bottomed in theupper portion of the bore 39 for the hydraulic motor 49. Since thehydraulic motor 46 is connected in parallel with the hydraulic motor 69through the cross conduits 5 2. and.53, the position of this motor willbe the same as the position of the hydraulic motor $9 and will operatein parallel therewith.

A check valve I is positioned in the conduit I59 for permitting flow offluid to the valve I10 half 83 since hydraulic fluid pressurels-exlstent in the chamber lld tending to resist upward movement of thehead 31. The pressure will be increased between the nozzle 63 and themold 82 until the pressure exerted by the ram it overcomes the pressurein the chamber I14 to thereby further advance the mold 84 in' an upwarddirection. The difierentialin pressure area of the piston 11 andthe-pistons 40' and GI deterbut preventing flow of fluid in a returndirection.

A pressure relief valve I16 is arranged to by-pass the check valve I15.The pressure relief valve, however, is set to by-pass pressure from theconduit I12 to the conduit I59 only when'the pressure in the conduit I12is above the pressure in the conduit I59, or above a predeterminedmaximum pressure.

When the actuating elements of the injection press are in the positionas disclosed in Figure 2, a valve I60 has been shifted to the positionwherein pressure from the conduit IBI has been directed through theconduit I62 to the fluid inlet 24 of the hydraulic motor I5 to retractthis motor. Fluid pressure has also been conducted through the conduitI65 to the fluid inlet II4 of the motor 3 and the fluid inlet [.30 ofthe hy'- draulic motor I26 whereby the actuating pistons of these motorshave been retracted to retract the ejector from the mold which is in the.ejection station B and to retract the pan II8 from Pressure fluid atthis time is' conducted through the conduit I59 through the valve I18 tothe fluid inlet 5| of the hydraulic motor 49, whereby the head 31 ismoved in its complete downward position. The mechanisms are then incondition to permit indexing of the turret 11 by actuation of suitableelectric controls, which electrical system will be hereinafterdescribed.

After the turret 11 has completed its indexing motion the solenoid I68is energized to shift the -way valve I60 to establish fluidcommunication between the conduit I6I and the conduit I63 to therebyconduct fluid under pressure to the fluid inlet 23 of the hydraulicmotor I5 and to conduct fluid .to the hydraulic motor H3 and I26 throughthe fluid inlets H5 and I3I respectively. It is of course understoodthat upon shifting of the valve I that the exhaust con- 7 duit I69communicates with the conduits I62 and I65 to permit return flow offluid from the hydraulic motors I5, H3 and I26 to the fluid storage tankI58.

Shifting of the valve I60 has not, however, in-

fluenced the fluid connection between the conduit I59 and the fluidinlet 5| of the hydraulic motor 49 so that pressure is still beingexerted within the chamber I14.

ediately upon connection of the conduit I6I with thecondults I68 theram." begins a forward stroke to engage the protruding portion 85 of themold 82' which has been indexed there-- adjacent. The'ram I8 lifts themold 82 from the turret TI and causes the upper mold half 83 to engagethe nozzle 63. Upon engaging the nozzle 88 pressure will be applied tothe upper mold mines-the pressure which will be applied to the mold 82to thereby clamp the mold halves to-- gether and to seal the nozzle withrespect the upper mold half 93. When the pressure in the hydraulic motorl5 overcomes the pressure in the chamber- I14 the injection cylinder 55will be moved upwardly'so' that the chamber 51 thereof will reciprocateover the injection plunger 34, whereby plasticmaterial which has beenheated in the injection chamber 51 will be ejected therefrom into themold 82. The upward movement of the injection cylinder will continueuntil the pressure of the pump I56 reaches its maximum value which issufiicient to force the plastic material within the mold into the minutecrevices in the mold cavity. A suitable dwell period is occasioned bymeans. of a' timing mechanism hereinafter. described with regard theelectrical system. I 1

Since the chamber I14 decreases involume upon upward movement of thehead 31 the fluid therein must be discharged to permit the head to moveupwardly. The pressure relief valve I16 will open when the pressurewithin the chamber I14 is a predetermined .value above the pressure inthe conduit I59 thereby by-passing the check valve I15 and permittingthe fluid in the chamber I14 to enter the discharge conduit of the pumpI56 and aid in supplying fluid to the.

main ram I8.

Concomitant with operation of the main ram I8 the hydraulic motors H3and I26 advance After the dwell" the electrical mechanism, hereinafterdescribed, breaks circuit to the solenoid I68 to permitthecompresslonspring I11 to shift the valve I68 to its former position, whereby theram l8, the plunger m and the plunger I28 will be retractedconcomitantly.

.Since pressure has been continuously established to the conduit I12 thehead 8] will be. moved downwardly uponreflll'ing of the chamber I14. If,for any reason, the injectionchamber 51 of the injection cylinder 55 isrequired to beoleaned of material existing in the chamber 51, the valveI18 can be shifted manually whereby fluid pressure is establishedbetween the conduit I59 and the conduit "I, which" operation will placethe upper end of the'bore 88 in communication withpressurefluid. Thehead will then be moved independentlyof the remainder of the mechanismof the injection machine to pass through a complete injection cycle toeject all material from the chamber l1. Such an operation would beperformed in case it is desired to change the grade or plastic materialto be ejected, or to change the color.

The mechanism for feeding plastic material I' into the injection chamber51. has heretofore been described, as well as the operation thereof.This mechanism will feed the proper quantity of material to theinjection chamber 51in direct proportion to the stroke of reciprocationthereof with respect to the plunger 34; Each cycle. or the injectionmachine will thus produce a work piece, the indexing mechanism operatingbetiated'by a momentary closing of the switch I18 whereby electriccircuit is established to the sole 'ing circuit is simultaneouslyestablished to the tween the injection cycles to index successive moldsadjacent the injection and ejection sta tions, and to open and close themolds by engaging the molds with the cam tracks 83 and at in a mannerheretofore described.

The electrical system forvcontrolling operation of the injection presscan be divided into two parts, one oi. which is the electrical controlmechanism for indexing the turret and the other is the mechanism forcontrolling the injection cycle. These two portions of the electricalcircuit are interconnected by means of'two limit switches lid and H9.The limit switch I18 momentarily closed upon completion oij an injectioncycle to energize electric circuit to the elec-.- trical controlscontrolling the indexingmechanism, while the limit switch I18 ismomentarily closed by completion of the indexing of the turret toinitiate the injection cycle. The limit switch 1118 is actuated by thehead 31 or by the ram it when in their completely retracted position sothat the indexing mechanism is initiated in actuation in response to thecompletion of the injection cycle. As heretofore described the ejectionand injection'mechanisms are operated concomitantly so that thecompletion of the cycle of one completes the cycle of the other.

The electricalcontrols for the indexing mechanism consist of a relay 088having an operating solenoid lti which actuates the relay blades I82 toclose the same against their respective contacts upon energization ofthe solenoid I 8|. A

1 normally closedelectric switch I83 is positioned in a holding circuitfor the solenoid I8I and is adapted to be momentarily opened by the armMil rotated by the electric 'motor I42 upon completion of the indexingcycle. Electric switches i8 1 and I85 are provided in series circuitwith the solenoid I8I, andare spring-actuated by .means of the springsI88 and I81 to normally retain the switchesin open position. The switchI84 is actuated by the ejection plunger II 6 to its closed position whenthe plunger H6 is in its fully retracted position The switch I85 isactuated by the work piece collecting pan I I8, or the mechanismoperating the pan, in a manner that the switch I85 is closed as long asthe pan is retracted from between the 'moldhalves 83 and 84. An electricswitch II! is pla'cedin the holding circuit of the solenoid I8I, whichswitch is actuated by movement of the cam tracks I05, as previouslydescribed.

The switch H2 is a double acting switch and initiation of the electricmechanism controlling has a contactor ll2a'operated in parallelther'emally open and is adapted to short circuit the switch I18 forpurposes hereinafter described.

The indexing motor I42 is thus actuated until the arm I43 strikes theswitch I 83 which.momentarily opens the circuit established therethroughto break the holding circuit for the solenoid I8I,

whereby the relay I82 drops out, halting operation of the electric motorM2. v

At the instant the switch I83 is opened the switch H8 is momentarilyclosed by the turret reaching the completion of its indexing motion,

thereby initiating an injection cycle hereinafter described.

As previously described, if the mold babies 83 and 84 should remain openwhen the cam track I 85 tends to force the same closed the electricswitch H2 will be opened, whereby the switch blades H2 and H20. willbreak circuit through the solenoids l8! and E88. It is to be understoodthat the breaking of the circuit through the switch l l2 occurs duringthe indexing motion and therefore if the switch blade H2 opens circuitthrough the solenoid iii i the indexing'motion will be immediatelystopped, and since the blade H2 is'in the holding circuit for the relayM2 the relay will drop out whereby if the blade H2 is forced closed theindexing cannot continue since the solenoid l8I cannot reenergize whenthe circuit is reestablished through the blade Illi. When this seriesofevents occurs the turret cannot be indexed by establishment ofmomentary circuit through the switch I18 since this switch has alreadyfunctioned upon the downward stroke of the head 3-1 or the ram I8whichever it is connected to, and it cannot. again function' at thistime. Hence, the manually operated push-button switch I98 is required toshort circuit the electric switch I18 to thereby reestablish circuit tothe solenoid I8I. This switch I can be retained-in the closed positionmanually until the troublesome die is indexed past the end of the camtracks I05at which time the switch I I2 will again'close circuit.

However, when the switch 'blade H2 is opened the switch blade IIZa isalso opened o that the solenoid I88 drops the relay I89 thereby breakingcircuitv to the electric switch I19 which controls the injection cyclefor a" complete automatic cycle of operation of the machine. When thisswitch I19 is closed momentarily by completion of the indexing of theturret electric circuit will not be made to the electric mechanismcontrolled thereby so that the injection press must be started manually.I

The electric control mechanism for controlling the injection cycle ofthe press consists of a relay I91 which is actuated by an electricsolenoid I98. The relay 181 controls energization of the solenoid- I68which actuates the valve I60 for controlling the direction of flow offluid to the hydraulic The operation of the indexing mechanism isinlmotor 85 and also establishes a holding circuit for the solenoidl98.--

To permit initiation of an injection cycle a relay I99 is provided whichis actuated by a solenoid 209. The relay I99 controls completion of thecircuit for the solenoid E98 and also establishes a holding circuitfor-the solenoid 288. The solenoid 208 is controlled by a normallyclosed limit switch 28! and a normally open limit switch I31. Thenormally closed switch 2M is actuated by the outward movement of thework piece collecting pan H8, and'is actuated in advance of actuation ofthe normally open limit switch I31. The normally open limit switch I3!is actuated by the comb I34, which comb indicates the presence orabsence of a work piece in the pan H8, as previously described. Th relay288 is closed continuously except for the short interval of time betweenthe operation of the switch 20I and the switch I31. The switch 28Ibreaks the holding circuit for the solenoid 280 to permit the relay I 99to drop out while the switch I31 momentarily closes circuit to thesolenoid 288 to reestablish vthe closing circuit for the same andthereby place the relay in condition to permit closing of the circuitthrough the solenoid I98 for initiation of an injection cycle.v

If a work piece should be absent from the collecting pan II8 when thesame is retracted the switch I31 will not be actuated so that the relayI99 will not close. This function at this point will not prevent theindexing of the turret by the mechanism heretofore described, but willprevent the initiation of an injection cycle since the electric circuitthrough the solenoid I98 cannot be completed with the relay I99 in theopen posi- Y tionr It is therefore seen that the control of theinjection cycle is responsive to the presence of a work piece in thework collecting pan II8. This safety measure is provided to insureejection of a work piec at the ejection station.-

The relay I89 is provided for determining whether thepress shall operateon a single manually controlled cycle or on a continuously automaticcycle. energized by closing the push button 282, the blades of the relayengage their cooperating contacts whereby circuit is established to theswitch -II9by means of the electric lines 203 and 284. A holding circuitis established for the solenoid I88 through the electric lines 285 and208.

Assuming the relays I89 and I99 to be closed, when t electric switch I19is momentarily closed by the rret 11, electric circuit is momentarilymade to the solenoid I98 through the electric lines 283 and 284, theswitch I19, electric lines 201 and 288, whereby the relay I91 is closedto establish circuit to the solenoid I68 through the lines 209 and 2I0.'A holding circuit is simultaneously made by the relay I98 through thelines 2II,2I2 and 208.

A timing mechanism for controlling the duration of the period ofadvancement of the ram isplaced in the electric circuit for the solenoidIf the solenoid I88 of this relay is I98. This timing mechanism isarrangedto retain the solenoid I68 energized for an interval of timewhich will besuflicient to permit injec-' tion of a plastic materialinto the om and will include suflicient time to provide a predetermineddwell period at the end of the injection stroke,

whereby the plastic material in the mold will be forced into thesmallest crevices in the mold cavity, and can include such time as willpermit a partial cooling oi the elastic in the mold before in the .moldby reversing the operation of the injection ram I8. The timing mechanismconsists of an electric motor 2I3 which drives a cam 2 I4, which cam 2Mactuates the electric switches ZI5 and 2I6. The electric switch 2I5 isplaced in the circuit for the solenoid I98 while the electric switch H6is placed in the electric circuit for the motor 2I3. An electric switch2'I'I is placed in parallel with the electric switch 2I6 and is adaptedto be momentarily closed wither by the head 3? or the ram I8 during theup stroke thereof, and represents the beginning of the injection cycle.The timer controls the reversing of the ram I8 after initiation of theoperation of the timer bythe switch 2I'I. The period of operation of themotor 2I3 is controlled by a variable resistor 2 I 8. Upon initiation ofan injection cycle, as heretofore described, the ram I8 orthe head 31will momentarily close the electric switch 2I'I whereby electric circuitis made to the timer motor 2I3 through the lines 2I9, 228, 22I and 222.Momentary making of this circuit starts the timing motor 2I3 whereby thecam 2I4 permits the switch 2I8.to close and thereby making electriccircuit for the motor 2I3 through the lines 2I9, 220, 223, 224 and 222.The period of time required for rotation of the cam 2 I4 into engagementwith the electric switch 2I5 determines the interval of time over whichthe injection and dwell will occur. When the cam 2H engagesthe switch2I5 electric circuit through the solenoid I98 is broken thereby droppingout the relay I91 and deenergizing the solenoid I88, whereby the 4-wayvalve I6!) is reversed and the ram is started on its retractionmovement. The electric motor 2I8 continues to rotate until the cam 2Hbreaks circuit through the switch 2I8.

An electric switch 225 is provided in series circuit with the solenoidI98 and is actuated by the head 31 to limit the maximum upward movementthereof with respect the injection plunger 34. This switch is providedto prevent undue upward movement of the head 81 should the head bereciprocated without a suflicient charge of plastic material therein, orfor any reason which would permit the head 31 to reciprocate upwardly toan extent which would damage the machine. Opening of the switch 225breaks circuit to the solenoid I98 to deenergize the solenoid I68 andreverse operation of the ram I8.

If it is desired to operate the injection machine without requiringoperation of the ejector mechanism or the work piece collecting pan H8,a selector switch 2281s provided which when in engagement with thecontact 221, short circuits the relay I99 whereby the press can beoperated without requiring operation of the ejector mechanism or thework piece collecting pan II8.

As previously described, when the molds 82 are prevented from closingwhen passing below the cam tracks I05 the switch blades H2 and 21: areopened whereby the relay I88 is deenergized 'and the injection machineis taken oil of full fied construction for opening the molds,-ejectingthe work pieces therefrom, and of closing the molds. There are twomechanisms provided which are similar in structure but which areslightly different in function, one of the mecha- The bores 233 and 233aare sealed at their lower ends by the packing glands 234. Thecooperation of the heads 232 and the bores 233 and Etta provideshydraulic motors for reciprocating the mechanisms 2% and 2 50.

The mold 82a is carried by the turret l'la into vertical alignment withthe plungers iii and this and the mechanisms 23d and 2% respectively.The molds ttct' being successively advanced from the mechanism 2% to themechanism etc. a

Ifhe mechanism tilt 'consistsloi a pair of track members it? which arepivotally mounted upon a pivot pinv carried by the plunger 23H. A'tension spring extends between the track members 237 and retains them inclosed position; as shown in Figure it. The mold tin has an upper half533a and a lower hall Ella. The upper mold halt 33m carrlesa pair oipins ii li which have enlarged headsiltil. The enlarged heads 2:32extend within cylinders Edi which are slidably mounted within bores 2%provided in the lower mold hall Zita. A pair oiplhs 2% is se cured tothe turret l'lcazid has enlarged heads which extend into the cylindersThe horizontally positioned pin till is carried within provided in thelower mold half this. of the pin it?! extending within slots in he sidewalls of the cylinders The upper mold half its carrlesrollers ital whichare adapted to engage the extending leds'es 240 represents the stationfor manipulation of thermold such as insertion of inserts, which stationhas been previously described. 7

To control the reciprocation of the plungers 23! and 23la 4-way controlvalves 254 and 255 respectively are provided. The control valves 254 and255 are manually actuated and have pressure fluid inlets 258 and 251respectively. The valve 254 has fluid conduits 258 and 259'connected toopposite ends of the bore 233, while the valve 255 has fluid conduits260 and 26! connected to op posite ends of the bore 23301;.

The mechanism 24!] consists of a pair of track members 262 which arepivotally mounted by a pin 263 to the plunger 23:11.. A tension spring264 urges the track members 262 to their closed position as disclosed inFigure 15. A lever mechanism is provided for opening the track members v262 against the tension of the spring 262 and the left-hand track memberact at consists of a lever arm ltil which is pivoted at 2th to theright-hand track me her 262. A short connecting link'ttll is pivotaysecured to the lever ltii at lit and is pivotally secured to This levermechanism is arranged to overthrow center in a snap acting manner toeither retain the track members 2th in open relation, as shown indotdash lines in Figure 15, or permit the spring to position the trackmembers 262 in closed position, as disclosed in full lines.

' The mechanism 2th is adapted to be reciprocated by means of themanually controlled valve ltd and the hydraulic motor associatedtherewith 4o pin Bill] carries an'ejection pin Elli) provided on thelower edges or the tract;-

memloers 23V. a

"When this mechanism 223% is reciprocated with respect th mold that thecam edges lot on the ledges strikes the rollers 25H to spread the trackmembers lit. to permit the same to pass over the rollers til. the track,members 'tt'l to their closed position therebyengaging the rollers iii;Upon upward reciprocation oi the plungersttl and tilinthe mold half Ma.The heads 2% of tho pins Ml The spring its will snap its" upper moldhalf his will be lifted from the low? will engage the upper ends of thecylinders 263 to move the same in an upwarddirection untilthe lower endsof the'slots 249 en age the pin 2t?! thereby lifting the same. when thepin 2" 11a when the plungers "I and 23M. are in their. upward positionwhereby the mold which was adjacent the mechanism 230 will be indexedintothe mechanism 240. The mechanism 230 represents the ejection stationB, while the mechanism at the initiation of the injection cycle, wherebythe mechanism Elli will pick up the upper mold half the and eject thework; piece from the lower mold hell did. Before the ending of theretraction portion oi the injection cycle the valve tat is manuallyoperated to reciprocate the mechanism t lt and thereby close the moldSta positioned thereunder. When the mechanism 2MB sets the upper moldhalf-lite upon the lower mold hall Eldon the lever arm disengages thetrash members ltd tram the rollers lltl to thereby permit imme diateretraction of the mechanism. by the hydraulic motor associatedtherewith.

When the turret lid is indexed the mold verti belly adjacent themechanism till is carried toward the injection station, while the openmold verticallyadjacent th mechanism tilt i carried .in its opencondition to the mechanism can, the track members it'll and it?respectively being in horizontal client to permit movement of themoldtic therebctween. n e It is of course understood that the manuallyoperated valves 2M and 255 could be operated automatically andincorporated within the full Having thus fully described my invention,what I claim as new and desire to secure by Letters Patent is v 1. Aninjection press comprising a stationary injection plunger, a movablehead carrying an injection cylinder for reciprocation upon saidplunger,-means for guiding movement of said positioned below saidinjection cylinder, and

movable head comprising a rod extending through said head and having apiston thereon, and a chamber in said head cooperating with said rod andforming a cylinder to provide a pressure motor for positioning saidcylinder with respect to -said plunger, a hydraulically actuated rammeans for successively advancing a plurality of molds into alignmentwith said injection cylinder,

plunger, an injection cylinder operatively associated therewith, aturret constructed and arranged to carry a, plurality of molds intosuccessive positions in alignment with said cylinder, a stationary camtrack associated with said turret for opening and closing of said moldsupon rotd tion of said turret, and a hydraulically actuated ram forcausing said molds to engage said cylinder and inject material into saidmold.

3. An injection press comprising an injection plunger,an injectioncylinder operatively associated therewith, a turret constructed andarranged to carry a plurality of molds into successive positions inalignment with said cylinder, a

stationary cam track associated with said turretfor opening and closingof said molds upon rotation of said turret, and a hydraulically actuatedplunger positioned adjacent said turret, said" plunger being constructedand arranged in a manner to move through said turret to lift said moldinto engagement. with said cylinder to cause injection of material fromsaid cylinder into said mold.

4. An injection press comprising an injection plunger, aninjection-cylinder operatively associated therewith, a turretconstructed and arranged to carry a plurality of molds into-successivepositions in alignment with said cylinder, a stationary cam trackassociated with said turret for opening and closing of said molds uponrotation of said turret, a hydraulically actuated plunger positionedadjacent said turret, said plunger being constructed and arranged in amanner to move through said turret to lift said 'mold into engagementwith said cylinder to cause injection of material from said cylinderinto said mold, and hydraulic-means associated with said lower camsurfaces which converge and diverge with respect to one another, andmeans on said molds engaging said cam track surfaces to open and closesaid molds upon rotation thereof wit respect said track. I

7. A plastic injection machine comprising an injection plunger, aninjection cylinder in operative association therewith, a turretconstructed and arranged for carrying a plurality of molds having upperand lower I old members into successive alignment with sa cylinder,means for causing engagement of said molds with said cylinder wherebymaterial is injected into said molds, means for indexing said turret aportion of a complete revolution, and a stationary cam track adjacentsaid turret having a lower surface substantially parallel to said turretand an upper surface which converges and diverges with respect to saidlower surface, said upper and'lower mold members having means engagingthe upper and lower surfaces of said cam track respectively whereby thelower mold member is retained from movement while theupper mold memberreciprocates with respect the lower'mold member to open and close saidmold upon rotation thereof with respect to said cam track.

8. A plastic injection machine comprising an injection plunger, aninjection cylinder in operative association therewith, a turretconstructed and arranged for carrying a plurality of molds having upperand lower mold members into successive alignment with saidcylinder,.means for causing engagement of said molds with said cylinderwhereby material is injected into said molds, means for indexing saidturret a portion of a complete revolution, a stationary cam trackadjacent said turret having a lower surface substantially parallel tosaid turret and an upper surface which converges and diverges withrespect to said lower surface,said upper and lower mold members beingconstructed and arranged to engage said cam track surfaces adjacentthereto to open and close said molds upon indexing 5. An injection presscomprising an injection I plunger, an injection cylinder operativelyassociated therewith, a turret constructed and arranged to carry aplurality of molds into successive positions in alignment with saidcylinder, a

stationary cam track associated 'with said turret for opening andclosing of said molds upon rotation of said turret, a hydraulicallyactuated plunger positioned adjacent said turret, said tuatedby movementof said cylinder for feeding material thereto in proportion to saidmovement,

6. A plastic injection machine comprising an injection plunger, aninjection cylinder in operative association therewith, a turretconstructed and arranged for carrying aplurality of molds intosuccessive alignment with said cylinder, means for causing engagement ofsaid molds with said cylinder whereby material is injected into saidmolds, means for indexing said turret a portion of acomplete-revolution, a stationary cam track adjacent said tuprethavinguppe r and of said turret, and means carried by said turret adjacentsaid molds for guiding the ope and and arranged for carrying a pluralityoftwo part molds into successive alignmentwith said cylinder, a pressureactuated plunger for raising said molds as a unitary structure from saidturret into engagement with said cylinder andfor moving said cylinderwith respect said plunger v thereby,-means for indexing-said turret-tosuccessively bring said molds into position in align-' meat-with saidinjection and said ejection statime, and means ior appiringfluidpressure in parallel to said injectionand ejectionsmotors tothereby inject and elect concomitantly, 11. A plastic-injection machinecomprisinz a bed, a fluid motorcarriedby said bed and having a ramextending therefrom, a. vertically positioned strain rod securedtosaid-bed, a turret rotatably carried upon said strain rod, 9. headreciprocably mounted upon said strain aboveia said turret (carrying aninjection cylinder in alignment with said ram, and a. stationary headsecu'redto said strain rod above said reciprocable head carrying aplunger in axial alignment with said cylinder.

12. A plastic injection machine comprising 'a a ram extending therefrom,a vertically positioned strain rod secured to said bed, a turretrotatably carried upon said strain rod, said turret being constructedand arranged to carry a pinrality oi equidistantly spaced molds, a headreciprocably mounted upon said strain rod above said turret carrying aninjection cylinder in alignment with saidram, a stationary head securedto said strain rod above said reciprocable head carrying a plunger inaxialalisnment with said cylinder, said turret having openings therein 7thronglrgwhich said ram can engage said mold in aligent therewith forlifting said mold into engagement with said cylinder ior'vancing saidcylinder over said injection plunger whereby material in said cylinderis injectedinto said mold,

a material feeding device carried bysaid stationary head, and meansactuated by each reciprocation of said reciprocable head for feedinmaterial to said cylinder in direct proportion to the stroke ofreciprocation thereof.

13. In an injection press the combination of a rotatably mounted turret,a plurality of mulbed, a fluid motor carried by said bed and having rialinto said molds, a station for ejecting work pieces from said molds,means for indexing successive molds into alignment with said injectionand election stations, an arcuately shaped cam track means associatedwith said turret having an inclined surface'for elevating the upper moldpart of successive molds when approaching said ejection station and adeclining surface for lowering the upper mold part of said molds whenapproaching said injection station, said molds having means engagingsaid cam track surfaces,

camv track means associated with the declining surface of said firstmentioned track means engaged by said cam surface engaging means on saidmolds for insuring closure oi said upper mold partuponthe lower moldpart when advancing toward the injection station, and means resilientlypositioning said last mentioned cam track means in spaced relation tosaid first mentioned camtracls means.

16. In an injection press the combination of pa, rotatablymountedtnrret, a plurality of multiple part molds having an upper and alower mold part, said molds being equidistantly spaced upon said turret,a station for injecting plastic material into said molds, a station forejecting work pieces from said molds, means for indexing successivemolds' into alignment with said injection and ejection stations, anarcuately shaped cam track means associated with said turret having aninclined surface for elevating the upper mold part of successive moldswhen approaching said ejection station and a declining surface forlowering the upper mold part of said molds mold part, said molds beingequidistantly spaced upon said turret, a station for injecting plasticmaterial into said molds, a station for electing work pieces from saidmolds, means for indexing successive molds into alignment with saidinjection and ejection stations, and an arcuately shaped cam track means"associated with said turret for elevating the upper mold part ofsadcessive molds when approaching said ejection station and for loweringthe upper mold part of said molds when approaching said injectionstation.

id. In an injection press the combination of a rotatably mounted turret,a plurality of multiple part molds having an upper and a lower moldpart, said molds being equidistantly spaced upon said turret, a stationfor injecting plastic material into said molds, a station for-ejectingwort: pieces'irom said molds, means for indexing successive molds intoalignment with said injection and ejection stations; an arcuately shapedv cam track means associated with said turret hav- ,ing an inclinedsurface for elevating theupper mold part of successive moldswhengapproaching said-election station and a declining surface" forlowering the upper mold part of said molds when approaching saidinjection statiomfsaid molds having means engaging said cam-tracksurfaces,

and cam track me associated with the declinins surfaceof said stmentioned track means engaged by said camsur face engaging means on saidmolds for insuring closure of the upper mold partupon the lower moldpart when advancing toward the injection station.

15. In an injection press the combination of a rotatably mounted turret,a plurality of multiple part molds having an upper and a lower moldpart, said molds being equidistantly spaced upon said turret, a stationfor injecting plastic mate- .35 tiple part molds having an upper and alower when approaching said injection station, said 'molds having meansengaging said cam track,

surfaces, cam track means associated with the declining surface of saidfirst mentioned track means engaged by said cam surface engaging meanson said molds for insuring closure of said upper mold part upon thelower mold part when advancing toward the injection station, meansresiliently positioning said last 'mentioned cam track means in spacedrelation to said'first mentioned cam track means, and means actuated bysaid last mentionedbam track means for halt ing operation of saidinjection machine.

17. In an injection press the combination of a rotatably mounted turreta plurality of multiple part molds having an upper and a, lower moldpart5 said molds being equidlstantly spaced upon said turret, a stationfor injecting plastic material into said molds, a station for ejectingwork pieces from said molds, means for indexing successive molds intoalignment with said injection and ejection stations, an arcuately shapedcam track means associated with said turret having an inclined surfacefor elevating the up- 'advancing toward the injection station, meansresiliently positioning said last mentioned cam track means in spacedrelation to said first mentioned cam track means, means actuated by saidlast mentioned cam track means for halting operation of said injectionmachine, said means actuated by said last mentioned cam track means alsohalting operation of'said indexing means. 18. In an injection press thecombination of a rotatably mounted turret constructed and arranged forcarrying a plurality of equidistantly spaced molds, a station forinjecting plastic material into said molds, a station for ejecting workpieces from said molds, means for indexing successive molds intoalignment with said injection and ejection stations, means at saidejection station for ejecting work pieces from said molds comprisingplunger means actuated by a hydraulic motor, means for locking saidturret in an indexed position with the sprue opening of a mold inalignment with said ejection plunger, said ejection plunger beingactuated to entersaid sprue opening in said mold to eject the work piecetherefrom.

19. In an injection press the combination of a rotatably mounted turretconstructed and arranged-for carrying a plurality of equidistantlyspaced molds, a station for injecting plastic material into said molds,a station for ejecting work pieces from said molds, means for indexingsuccessive molds .into alignment with said injection and ejectionstations, means at said ejection station for ejecting work pieces fromsaid molds comprising plunger means actuated by a hydraulic motor, meansfor locking said turret in an indexed position with the sprue opening ofa mold in alignment with said ejection plunger, said ejection plungerbeing actuated to enter said sprue opening in said mold to eject thework piece therefrom, and means actuated concomitantlyv with actuationof said ejection plunger for catchinjection and ejection stations, meansat said ejection station for ejecting work' pieces from said moldscomprising plunger means actuated by a hydraulic motor, means forlocking said turret in an indexed position with the sprue opening oi amold in alignment with said ejection plunger, said ejection plungerbeing actuated to enter said sprue opening in said mold to eject thework piece .therefrom, means actuated concomitantly with actuation ofsaid ejection plunger for catching said work piece when ejected fromsaid mold, and means actuated by the presence of a work piece in saidwork piece catching device for indicating the presence or absence of awork piece therein.

'21. In an injection press the combination of a rotatably mounted turretconstructed and arranged for carrying a plurality of equidistantlyspaced molds, a station for injecting plastic material into said molds,a station for ejecting work piecesfrom said molds, means for indexingsuccessive molds into alignment with said injection and ejectionstations-means at said ejection staand means actuated by the presence ofa work piece in said work piece catching device for indicating thepresence or absence of a work piece therein, said last mentioned meanshalting operationof the press upon absence of a work piece in said workpiece catching device.

22. A plastic injection machine comprising a stationary injectionplungenan injection cylinder, a hydraulic motor associated with saidcylinder having pressure fluid continuously applied to one side thereof,a double acting hydraulic motor for actuating a ram, said ram beingadapted to move molds associated with said injection cylinder forcausing injection of material therein, valve means for controllingdirection of flow of fluid to said ram rotor, a variable deliveryconstant pressure pump for supplying fluid to said motors, a check valvein the supply line to said first mentioned .motor, a pressure reliefvalve arranged to by-pass said check valve, and means for shifting saidvalve means for actuating said ram to advance said mold into engagementwith said cylinder and said cylinder over said plunger thereby causingfluid to flow from said first mentioned motor to said second mentionedmotor.

23. A plastic injection machine comprising an injection unit having ahydraulic motor for actuating a ram for causing injection of materialinto a mold, an ejector mechanism having a; hydraulic motor foractuating the same, a hydraulic motor for actuating a mechanism disposedadjacent said ejector mechanism for collecting the work piece as'ejected from the mold, a variable delivery constant pressure pump iorsupplying fluid under pressure to said motors. means interconnectingsaid motors to cause concomitant action thereof, and means in the supplyline to said ejector motor for the retarding operation thereof withrespect said work piece collecting motor.

24. A plastic injection machine comprising a turret, means for indexingsaid turret, a plastic injection unit including a ramactuated by ahydraulic motor, means for actuating said indexing mechanism in responseto the full retraction position of said ram, means for halting saidindexing motion, means for initiating actuation of.

said ram for an injection cycle, means actuated by the initiation ofsaid injection cycle for controlling the time interval of said cycle,said last mentioned means providing means for reversing actuation ofsaid ram to position. said ram in' its initial position to re-actuatesaid indexing means.

25. An injection press comprising an injection plunger,- an injectioncylinder associated therer with, a turret disposed adjacent saidcylinder, 9.

' moving successive molds from said turret into tion for ejecting workpieces from said molds comprising plunger 'mea'ns actuatedday ahydraulic motor, means for locking said turret in an indexed positionwith the'sprue opening of a mold in alignment with said ejectionplunger, said ejection-plunger being actuated to enter said sprueopening in said mold to eject the work piece therefrom, means actuatedconcomitantly with actuation of said ejection plunger for catching saidworkpiece when ejected from said mold,

' engagement with/said cylinder when advanced into alignment therewith.

26. An injection press comprising a stationary injection plunger, aninjection cylinder reciprocably associated therewith and having an injection nozzle extending therefrom, a turret disposed adjacent saidcylinder, a-plurality or multiple part molds removably supported on saidturret, means for actuating said turret for successively advancing saidmolds into coaxial alignment with said injection nozzle, means adjacentsaid molds for maintaining coaxial, alignment of said mold parts whensaid molds are removed from said turret, and a pressure motor forremoving the molds from said turret into engagement with said nozzle toadvance said cylinder over said plunger by pressure applied upon saidnozzle to cause material in said cylinder to be injecmd into said molds.

27. an injection press comprising an injection plunger, an injectioncylinder associated therewith having an injection nozzle extendingtherefrom, a turret having a plurality of molds removahly carriedthereby constructed and arranged to bring successive molds intooperative ranged to bring successive molds into operative position withrespect to said cylinder, and a pressure actuated plunger for liftingsaid molds from. said turret into engagement with said nozzle to sealthe same upon the mold and to advance said cylinder upon said injectionplunger to apply closing pressure upon said mold and eject mate rialfrom said cylinder into the mold.

\ 29. An injection press comprising an injection plunger, an injectioncylinder associated therewith having an injection nozzle extendingtherefrom, a .turret'having a plurality of two part molds removablycarried thereby and constructed and arranged to bring successive moldsinto operative position with respect to said cylinder, and a pressureactuated plunger movable through said turret for lifting said molds mmsaid turret into engagement with said nozzle to seal the same. upon saidmolds and apply closing pressure upon said molds. 1

to. an injection machine comprising a stationary injection plunger, aninjection cylinder reciprocable thereon, a pressure motor forpositioning said cylinder in the same determined positionupon saidplunger after each reciprocation stroke with respect to the same,movable means disposed beneath said cylinder and having a. plurality ofindividual molds removably through means of said mold, said firstmentioned motor resisting said movement whereby clamping pressure isapplied to said mold during injection of material thereinto andreturning said cylinder to its starting position upon said plunger upon1 reversing the flow of fluid to the second mentioned motor.

32. An injection press comprising a stationary injection plunger, aninjection cylinder reciprocable thereover having an injection nozzleextending therefrom, a hydraulically actuated ram positioned inalignment with said nozzle, a turret table disposed between said ram andsaid cylinder, a plurality of two part molds removably carried upon saidturret table, said molds being constructed and arranged to permit axialmovement of the parts relative to each other without complete separationthereof, means for indexing said turret table to successively positionsaid molds into alignment with said cylinder and said ram, and meansifor actuating said rain to lift the mold in alignment therewith fromsaid turret table into engagement with said nozzle and through means orsaid mold to move said cylinder with respect to said plunger to therebyeject material from said cylinder into said mold.

i 53. An injection press comprising a stationary injection plunger, aninjection. cylinder reciprocable thereover and having an injectionnozzle supported thereon, said means-successively adextending therefrom,a hydraulically actuated ram positioned in coaxial alignment with saidnozzle, a turret table disposed between said ram and said cylinder, aplurality oi two-part molds removably carried upon said turret tablesaid molds being constructed and arranged to permit axial movement orthe parts relative to each other without complete separation thereoi,means for indexing said turret table to successively position said moldsinto coaxial alignment with said nozzle and said ram, said turret tablehaving openings therein in alignment with said molds through which saidram can reciprocate, means toactuate said ram to lift the mold inalignment therewith from the turret and into engagement with said nozzleto reciprocate said cylinder with respect to said plunger through meansoisaid nozzle to thereby eject material from said cylinder into saidmold, and a pressure actuated motor connected to said cylinder andhaving fluid pressure continuously applied thereto to resist movement ofsaid ram and apply clamping pressure upon said mold during advancementof said ram through said engaging nozzle. I

34. An injection press comprising a stationary injection plunger, aninjection cylinder reciprocable thereover and having an injection nozzleextending therefrom, a hydraulically actuated I removably carried uponsaid turret table, said tionary injection plunger, an injection cylinderreciprocalole thereon, a pressure motor for positioning said cylinder inthe same determined position upon said plunge r aiter each reciprocationstrolre withrespect to the same, movable means disposed beneath saidcylinder and having a plurality oi individual molds removably supportedthereon, said means successively advancmg said molds into axialalignment with said cylinder, and a single pressure motor forsuccessively removing saidmolds from said supporting means intoengagement with said cylinder and tor advancing said cylinder over saidplunger molds being constructed and arranged to permit axial movement ofthe parts relative to each other without complete separation thereof,means for indexing said turret table to successively position said moldsinto coaxial alignment with said nozzleand said ram, said turret tablehaving openings therein in alignment with said moldsthrough which saidram can reciprocate, means to actuate said ram to lift the mold inalignment therewith from the turret and into engagement with said'nozzleto reciprocate said cylinder with respect to said plunger thr ugh meansof said nozzle to thereby eject manv a1 0 ing fluid pressurecontinuously appiied thereto to resist movement of said ram and applyclamping pressure upon said mold during advancement of said'ram throughsaid engaging nozzle and returning said cylinder to its startingposition upon said plunger when said ram is retracted.

35. A plastic injection machine comprising a bed, a fluid motor carriedby said bed and having a ram extending therefrom, a ver'iicallypositioned strain rod secured to said bed and-having an enlarged portionforming a piston of a fluid motor, a turret rotatably carried upon saidstrain rod, said turret being constructed and arranged to carry aplurality of molds spaced equidistantly in an annular ring upon saidturret, a head slidably mounted upon said strain rod above said turretcarrying an'injection cylinder in alignment with said ram and having abore of the same diameter as said piston and cooperating therewith toprovide a fluid motor to reciprocate said head on said strain rod, astationary head secured to said strain rod above said reciprocable headcarrying a plunger in axial alignment with said cylinder, said turrethaving openings therein through which said ram can engage the mold inalignment therewith for lifting said mold into engagement with saidcylinder for advancing said cylinder over said injection plunger wherebymaterial in said cylinder is injected into said mold, said secondmentioned fluid motor opposing movement of said ram to apply clampingpressure on said mold and retain some in engagement with said cylinder.

H WARREN R. TUCKER.

